1. Field of the Invention
The present invention relates to an apparatus for detecting position information of a moving object, and more particularly to an apparatus for detecting position information of a moving object on which is mounted a device for storing position information at a predetermined location of a road, and which controls a moving object to read its current position information from information stored in the device using an RF (Radio Frequency) signal, thereby detecting correct position information of the moving object.
2. Description of the Related Art
Typically, various moving objects (e.g., ships, airplanes, and vehicles, etc.) include a navigation system for determining a current position of the moving object and for informing a driver of the moving object of an optimum path from the current position to a desired destination. The navigation system determines a current position of a moving object using a GPS (Global Positioning System).
GPS is an abbreviation of Global Positioning System, which is for detecting current position information of moving objects using 24 artificial satellites in orbit around the earth at an altitude of about 20,183 km. In more detail, if electronic waves (e.g., a GPS signal) transmitted from the satellite recognizing a correct position of a corresponding moving object are transmitted to a GPS receiver mounted to an observation point, the GPS receiver is adapted to calculate a duration required for the electronic waves to be received, thereby calculating a current position of an observation point.
Therefore, a conventional navigation system mounts a GPS sensor to a predetermined location of a moving object, controls the GPS sensor to analyze a GPS signal received from more than four satellites, and thus determines a current position of the moving object.
Data received from the GPS unavoidably includes an ionospheric error, a satellite error, and a multipath error. If a moving object (e.g., a moving vehicle) having a GPS sensor travels a variety of road conditions such as huge/high building zones, a zone close to roadside trees, or a tunnel, it cannot receive a GPS signal, meaning that the conventional navigation system cannot inform a driver of correct position information.
To solve this disadvantage, the conventional navigation system further includes a specific device such as a DR (Dead Reckoning) sensor for detecting relative position information and traveling direction information of a specific moving object using previous position information of the moving object. However, such a conventional navigation system still has a disadvantage in that the DR sensor unavoidably includes a variety of errors such as an initial alignment error and a conversion-factor error.